The invention relates to a multiple tube bundle heat exchanger. In other words, the invention relates to a heat exchanger configuration that includes a plurality of flow-interconnected heat exchange tube bundles. The flow interconnection may relate either to the medium flowing through the tube bundles or to the medium flowing around the tube bundles, or to both.
Multiple tube bundle heat exchangers are already in the prior art. For example, Switzerland Patent No. CH 586 882 describes a counter-current tube bundle heat exchanger in the form of an in-series, tube bundle heat exchanger. In that heat exchanger, a common housing has disposed in it a plurality of tube bundles that are flow-connected in series and through which the primary medium flows in succession. All the tube bundles run between two tube sheets common to all the tube bundles, and the plenum chambers above each of the tube sheets are subdivided into partial chambers to form an inflow distributor chamber for the primary medium for distribution to the tubes of the first tube bundle, then a series of connecting chambers, disposed above the one tube sheet or the other, for connecting respectively the outlet ends of the tube bundle to the inlet ends of an adjacent tube bundle, and, finally, an outlet collecting chamber above the outlet ends of the last tube bundle in the flow series connection. Between the individual tube bundles are disposed, in the housing, partitions that respectively have fluid transfer orifices near one tube sheet or the other so that the secondary medium flows first into a first tube bundle chamber and then passes through the fluid transfer orifices from tube bundle chamber to tube bundle chamber and finally out of the last tube bundle chamber into an outlet.
It is accordingly an object of the invention to provide a multiple tube bundle heat exchanger that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that provides a configuration making it possible, on a modular basis, to construct economically the most diverse tube bundle heat exchanger configuration that is variable to the greatest possible extent both in terms of size and in terms of the flow configuration or of the routing of the primary medium and secondary medium.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a multiple tube bundle heat exchanger, including a number of tube bundles, each of the tube bundles being formed as a self-contained integral unit having two axially spaced tube sheets and a plurality of heat exchanger tubes each with opposite axial ends, the two tube sheets mounted at the opposite axial ends of the heat exchanger tubes, a casing having a tubular portion substantially coextending with the tube bundles and having an interior subdivided by partitions into a plurality of axial chambers, a number of the axial chambers corresponding to the number of the tube bundles, each of the chambers receiving one of the tube bundles, two opposite axial ends, and flanges disposed at the two opposite axial ends, and head pieces removably mounted to the flanges, each of the head pieces having walls defining at least a first wall portion of a plenum chamber, and the two tube sheets of each of the tube bundles respectively sealing an adjacent one of the head pieces and forming at least a second wall portion of a respective plenum chamber of the adjacent one head piece.
In accordance with another feature of the invention, the partitions have at least one fluid transfer opening adjacent at least one of the two opposite axial ends of the tubular portion to allow fluid flowing through the interior of the tubular portion to pass between adjacent ones of the chambers.
In accordance with a further feature of the invention, the at least one fluid transfer opening is selectively obturated.
In accordance with an additional feature of the invention, the partitions have fluid transfer openings adjacent the two opposite axial ends of the tubular portion to allow fluid flowing through the interior of the tubular portion to pass between adjacent ones of the chambers.
In accordance with yet another feature of the invention, the fluid transfer openings are selectively obturated.
In accordance with yet a further feature of the invention, there is provided a separate intermediate piece disposed between at least one of the two opposite axial ends of the tubular portion and an adjacent one of the head pieces to form an axial extension of the tubular portion.
In accordance with yet an added feature of the invention, the intermediate piece has partitions forming axial extensions of the partitions of the tubular portion.
In accordance with yet an additional feature of the invention, the partitions of the intermediate piece have fluid transfer openings to allow fluid to pass between adjacent ones of the chambers in the tubular portion.
In accordance with a concomitant feature of the invention, there is provided a separate intermediate piece disposed between at least one of the two opposite axial ends of the tubular portion and an adjacent one of the head pieces to form an axial extension of the tubular portion, the intermediate piece having partitions forming axial extensions of the partitions of the tubular portion, and the partitions of the intermediate piece having fluid transfer openings to allow fluid to pass between adjacent ones of the chambers in the tubular portion.
The concept according to the invention provides for using standard heat exchanger tube bundles together with standard housing sub-assemblies that allow a multiplicity of combination possibilities and, of course, also heat exchanger configurations of different size.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a multiple tube bundle heat exchanger, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.